Thermostat



Dec. 29, 1953 W. C. BROEKHUYSEN Filed Feb. 2l, 1950 mm) f THERMOSTAT 3 Sheets-Sheet l lIl- .9

Z7 MIHHM...y

INVENTOR.

OMLZZM Ww 3 Sheets-Sheet 2 I N VEN TOR. iff/mm mffn TTO/TNEYS Dec. 29, 1953 w. c. BROEKHUYSEN THERMOSTAT Filed Feb. 2l, 1950 Dec 29, 1953 w. c. BROEKHUYSEN THERMOSTAT 3 Sheets-Sheet 3 Filed Feb. 2l, 1950 ayu@ E W Zw w Y ILM 0%,ww w.

MMMWM Patented Dec. 29, 1953 UNITED STATES PATENT OFFICE THERMOSTAT 'William C. Broekhuysen, Brooklyn, N. Y. Application February 21, 1950, Serial N o. 145,475

(Cl. 20D-137) 16 Claims.

This invention relates to a functionally and structurally improved thermostat for controlling the opening and closing of a desired circuit or circuits to in turn control mechanisms such as cooling and heating apparatus.

It is an object oi the invention to provide a thermostat, the mechanism of which may be wholly enclosed so as to be maintained free from contact with dust and other material which would cause faulty operation; such thermostat responding with minimum lag to temperature changes.

A :further object is that of providing an apparatus of this type which will operate perfectly even when installed at points where it is subjected to constant vibration and rapid and numerous variations in temperature; the assembly being capable of ready adjustment-when this is required-by manipulation of the exterior parts or surfaces and this adjustment not being critical.

Among other objects of the invention are those of providing a compact and relatively small unit, the parts of which will be free from friction or back lash so that a stable assembly is furnished. Moreover, th-e unit will include relatively few parts, each individually simple and rugged in construction, these parts being capable of manufacture by quantity production methods and assembly at minimum expense to furnish a thermostat or control having a long effective life free from all difficulties.

With these and other objects in mind, reference is had to the attached sheets of drawings illustrating practical embodiments of the invention and in which:

Fig. 1 is a sectional side view of a thermostat;

Fig. 2 is a longitudinal section taken along the lines 2 2 and in the direction of the arrows as indicated in Fig. 1;

Fig. 3 is a bottom plan view of the device;

Figs. 1i and 5 are transverse sectional views taken along the lines 4 4 and 5 5 respectively and in the direction of the arrows as indicated in Fig. 1;

Fig. 6 is a fragmentary view of the upper portion of an apparatus embodying alternative structure over that shown in the earlier iigures;

Fig. '1 is a sectional View taken along the lines 1 1 and in the direction of the arrows as indicated in Fig. 6;

Figs. 8 and 9 are views similar to Figs. 1 and 2 but showing alternative forms of structure;

Fig. 10 is a fragmentary view showing in section the upper portion of the unit and illustrating a further arrangement of the parts;

Fig. 11 is a view similar to Fig. 1 but showing still another arrangement;

Y bracket 24 in contact Fig. 12 is a sectional view taken along the lines I2 l 2 and in the direction of the arrows as indicated in Fig. 11;

Fig. 13 is a transverse sectional view taken along the lines |3 |3 and in the direction of the arrows as also indicated in Fig. l1;

Fig. 14 is a sectional side view illustrating a heating element in association with the thermostat assembly;

Fig. 15 is a transverse section taken along the lines |5 |5 and in the direction of the arrows as indicated in Fig. 14;

Fig. 16 is a sectional illustrating one manner stat;

Fig. 17 is a top plan view thereof; and

Fig. 18 is a front view of the assembly as shown in Fig. 16.

Referring primarily to Figs. l to 5 inclusive, the numeral 20 indicates a tubular casing preferably of brass and which in section may be circular in side view of an assembly of mounting the thermooutline. The lower end of this casing is reduced as at 2| and terminates in a constricted neck portion 22. Filling the latter and extending into the casing is a strip 23. This strip serves as a mounting for certain of the parts as hereinafter described and is preferably formed of metal having a low co-ecient of expansion.

At its inner end strip 23 has secured to it a with one of its faces. To its opposite face a spring 25 is secured. This spring may be approximately square and in turn mount a supporting member 26. Member 26 forms part of a rigid arm assembly which includes also spaced webs 3l and angle bracket 21. The connections between 'these parts may be conveniently effected by spot welding. The lower end of a spring 28 is secured to bracket 21. Springs 25 and 28 are formed with openings through which extends a spring strip 29. The latter is secured adjacent its opposite ends to brackets 24 and 21 respectively. A strut member 30 has its lower end secured to the upper end of spring 28; its upper end being secured against movement with respect to the inner face of tube 2U adjacent the upper end of the latter. All of these points of securing or attachment are conveniently achieved by spot welding.

Strut member 30 is formed of metal having a low co-enicient of expansion. The assembly provided by springs 25, 28 and 29 furnishes a iiexion connection. Thus, strip 23 and the arm assembly provided by supporting member 2S and the parts carried thereby are pivotally connected as are also the arm assembly and strut 36. Tube 20 being formed of a metal, having a high co-eilicient of expansion such as brass and strip 23 and strut being secured to that tube and being formed of metals having a negligible co-eflicient of expansion, it follows that the iiexion coupling afore-described will transmit movement to the other parts of the assembly. This would occur as the body of tube 2D is subjected to either cooling or heating.

To supporting member 26 a spring 32 is secured by, for example, spot welding. This spring may have a width less than the distance between webs 3 It carries at its upper end a transverse bar 33, the face of which bears against the rear edges of webs 3|. The connections: between spring and bar may again be conveniently effected by spot welding. The upper end of tube 23 is closed by a cap 34 and air flow between the parts may be prevented by solder. Passing through the cap are leads or electrodes 33 and 31. To

provide insulation and also to provide proper i seals, bodies of glass 38 may rbe interposed hetween the leads 36 and 3 1 and the adjacentsurfaces ofthe cap. This structure may be established by raising the temperature to the melting point of the glass. A boro-silicate glass may be employed which may have substantially the same co``efiicient of expansion as the material of cap 34 and leads 3e and 31. Cap v34 may also be pierced by an evacuating gas or liquid charging Lead 31 supports at its inner end contact 43 with which a contact 4| cooperates. The latter is mounted uponthe iiattened outer end oi a wire strip 42 to which is secured a body 4 3 of di-electric material. y it may pass into the space existing between webs 3 Preferably body 43 is formed of glass which ils bonded to the body of wire 42. The inner or lower end of that wire may also be nattened and secured to a spring 44 attached to the lower or inner end of electrode or lead 3 3. Spring 44 is biased so as to urge contact 4| in the direction of contact 40, to assure proper electrical engagement. To support tube 20 the lower or attened end of the latter as defined by neck portion 22v is disposed within a socket or cup 45. The base of this socket can be provided with opposed threaded bores within which plugs 4 3 are'mounted. In that case tube 20 may be provided with a reduced or socket-entering portion dened by a iiange 4 1 which will b ear against the upper edge of'cup 45. Under these circumstances and 'with the reduced portion of the tube bearing in supporting relationship against the inner face of'cup 4 5 it is apparent that by retracting one of the plugs 46 and projecting the other oi the same, theneck portion 22 of the tube and the strip carried thereby may be ax1ally deiiected. In otherwordsit will be rocked around a pivot zone generally dened by the point of juncture of the reduced portion 2| and strip 23. 1f a cup or equivalent supporting portion is not employed, then the same pivoting action may be secured by bending or swinging neck portion 22 to the left or right as viewed in Fig. 1 this being achieved bythe use of a pair of pliers or any other suitable tool.

As will be understood in operation with respect to the mechanisms as shown'in Figs. 1 tof5, leads 3Bvand 31 will be connected to a source of current supply and with the unit to be controlled.' That unit may embrace a. refrigerating apparatus.

Assuming the parts to be properly adjusted with respect to each other, then if the vaissemliily 'is' subjected to heat-'as would be the case if warm fThe diameter er1-.his body is suon that .1;

z3. air is passing in contact with the outer surface of tube 20--the latter will expand. Due to the low co-eicient of expansion inherent to strut 30 and strip 23 they will not respond by an axial lengthening of their assembly to any degree corresponding to the axial enlargement oi tube 20. Consequently a pull will be exerted by strut 30 and strip 23 on the interposed flexion coupling. Due to the manner in which the webs 3| and supporting member 26 are connected to this coupling, that assembly will move in a clockwise direction as viewed in Fig. 1. Because spring 44 is urging contact 4| into circuit-closing position such movement of the parts will have no effect n lthe controlled circuit, which will remain closed.

If, however, the exterior of tube 2G is subjected tocooling action, then the axial length of that tube will shrink, but any shrinkage of strip. 23 and strut 30 will vnot occur toa corresponding extent. Therefore, webs 3| or their equivalents will begin to shift in a counterclockwise direction as viewed in Fig. 1. Under continued movement bar 33 will engage di-electric body 43. Due'to the fact that spring 32 has greater tension than spring 44, such engagement will result in lthe latter spring being iiexed, causing a separatin of contacts 40 and 4| and an opening of-"the circuit which they control. Further "Shifting will bring the globule `43 into` contact Vwith lead or electrode 36. If Still further cooling or-'the parts occurs, then'bar 33 willl lift outofcontact with the edges of webs 3| `due to the provision of spring 32. Accordingly, dangerousv stresses which might be set up by' an over-cooling of the parts will be avoided'and no damage will coeur tothe mechanism. Despite this safety provision it will be apparent that the closing and opening of the contact ordinarily occurs inY a` vpositive manner. This is because bar 33fin eiiect moves as a unit with webs`3| and supporting memberf2`6 and, in contact with element '43, directly controls the engagement or separation of contacts 4G'- and 4|. Asy is apparent a unit of this type would," in

r many respects, be preferred for the purposev of controlling a'refrigerating or cooling apparatus. However, by, for example, employing a suitable control involving a relay it might be employed to control the functioning of heating apparatus. When it is necessary to adjust the temperature setting which is incorporated in the'thermostar se that contactera and 4|' remain' leerigagement until a lower temperature isreached, orso that these contacts do not engage'until ahigher temperature is reached, this is "achieved by adjusting theY neck portin 22. This is accomplished by the use oi suitable tools or by flexing the neck portion through the retraction and projection'ofrplugs 'Suchas '46. If the bendin g or adjustment "of the 'parts'results' in the flexion assembly (as viewed in Fig. 1) being shifted to the left, then contacts lill-4| will'separateV at a higher temperature. Y Conversely a shifting'of this lassembly in a clockwise direction will cause bar 33 andthe parts coupled therewith to be similarly shifted. Therefore, that bar will not cooperate 'with element 43 to shift contact 4| until a lower temperature is reached.

The foregoing adjustment of the parts isA not at. all critical. Rather, insteadl cia deflection of strip 23 resulting in `a magnified movement of the structure carried by supporting member`26, the" degree of that mevement' wm beeutetanriaiiy equal from rhe'ee'er the' exin eolipling through to the bar 33. The amount of Vshifting will be generally and substantially equal to the shift of bar 33 in a lateral direction.

In the structure of Figs. 1 to 5, a mechanism is furnished in which the contacts open or close at a relatively slow rate as the temperature varies.

4This results in little or no differential between opening and closing temperatures. If a positive temperature diierential is desired, then a structure such as has been suggested in Figs. 6 and 7 may be employed. As will be seen, in those views there has been illustrated the upper portion of the thermostat assembly 'and the same reference numerals have been employed in these gures to designate similar parts to those heretofore described and shown in the earlier iigures.

However, it will be observed that in Figs. 6 and 7 ak magnetic structure is associated with the mechanism in the region of the contacts. Thus, an armature is interposed between contact 4l and strip 42. This armature has ben indicated by the numeral 48 and is formed of high-permeability iron. A magnet 49 is mounted upon the electrode or the lead 31 and t0 the rear of con- The arms of this magnet extend outwardly so that contact 40 is preferably housed within the crotch of magnet 49.

The parts are conveniently so proportioned and of such value that, for substantially the last .001" of movement of the contacts 40 and 4l towards each other, the rate of increase of the magnet pull exceeds the rate of resiliency of the supporting structure of which the webs 3| form a part. Also, the amount of attraction or pull should exceed lany separating tendency exerted by the spring 44 or functionally equivalent parts. Additionally, the parts should be so proportioned that a small gap will remain between the magnet 49 and its armature 48. In this manner it will be apparent that a snap yaction will occur such that a rapid opening or closing of the circuit will follow, when the parts have once been biased or shifted in a given direction.

In the form of structures shown in Figs. 8 and 9 the same reference numerals have again been employed to indicate the parts which have heretofore been described. In these views, however, Y

it will be noted that the lower end of the casing 20 is constricted as at 50 to support a. relatively heavy strip 5l formed of metal having a low coefficient of expansion. A strut 53 formed of similar material has its lower end secured to strip l and its upper end secured to the inner face of tube or casing 20 adjacent the upper end of the latter. This strut is preferably in the form of a channelled or flanged member. In-

ytermediate its ends the flanges are notched as indicated at 54 to preferably provide a V structure, the arms of which are Widely spread. In

line with this notch and adjacent the points of `connection of the strut with the casing 20 and strip 5l, its web may be pierced as indicated at 55. So pierced three fiexure points are provided. Two supporting members 56 are secured to the sides of strut 53 at a point short of the .point of notching 54. Thus, in effect, they provide an extension arm of the lower portion or leg of the strut. This arm supports bar 33 attached to the end of spring 32 also secured to strut 53 and allows a movement of the bar as heretofore described in Figs. 1 to 5. Again in this structure the parts are preferably secured to each other by spot welding or in -any other desired and proper manner.

Contrary to the structure described in Figs. 1 to 5 a cooling of the unit as in Figs. 8 and 9 results in contact 4| being permitted to move to the right as viewed in Fig. 8 and thus engage contact 40 to close the circuit. A warming of casing 20 by being exposed to heat causes the latter to distend axially with consequent movement of the supporting arm 56 to the left. This will result in contacts 40 and 4I separating. It will again be found that in this assembly of the parts an adjustment may be effected by simply bending the constricted lower portion 50 and the enclosed strip 5I to shift the upper end of the latter in the desired direction. Such shifting will carry with it the mounting block 52 and the lower end or leg of strut 53. I1 the direction of shift of mounting block 52 is in a clockwise direction as viewed in Fig. 8, then supporting arm 56 will tend to move in a counterclockwise direction. In this connection it will be understood that the side flanges of the arm assembly provided by the side webs 56 are secured by spot welding or otherwise to the side lianges of strut 53 at a point below the notch 54. Under these circumstances the temperature setting is lowered by this adjustment. As in Figs. l to 5, the lateral shift of bar 33 is very much less with this arrangement of the parts than would be the case if a single rigid member were employed extending from the point of juncture of strip 5l and casing 20 through to bar 33. The structure of Figs. 8 and 9 is somewhat similar to that shown in the earlier figures. However, the expanding and contracting movement of the tube or shell 20 is not amplied as much in the Zones of the contacts as in the earlier structure. Nevertheless, the force of movement in the zone of the contacts is high g and the assembly is extremely rigid. Therefore,

it is suitable for use with heavier loads under adverse conditions of vibration.

In the event it is desired to rearrange the parts so that the contacts will engage in response to a rise in temperature instead of opening under those circumstances, a structure such as has been shown in Fig. 10 may be employed. That structure corresponds generally to the one just described in connection with Figs. 8 and 9. However, as will be seen in Fig. 10, the supporting Webs 56 do not have their right hand edges engaging with the cross bar 33. Rather, this bar is mounted by a spring 5l secured to the strut 53 at a point below the V notch 54 and the spring extends tangentially between webs 56 and mounts at its upper end a bar 58. Under the influence of spring 51 that bar bears against the left hand edges of webs 56. Therefore as these webs move in a clockwise direction as viewed in Fig. 10, the bar will engage with the di-electric or spherical element 59 to cause a flexion of spring 60. Accord ingly, contact 6l which is supported by spring 60 will be caused to move out of engagement with contact 62 which is mounted by electrode or lead 36. As will also be seen in this view electrode or lead 31 mounts spring 60.

In Figs. 11 to 13 the tube of casing 20 has its constricted lower portion mounting strips 63 and 64. Each of the latter has secured to it strut members 65. These members have their upper een i an@ il.

amaraneniie ettaenett te. the. race. of time. 2.1!` and ireiintine blacks; 6.6 end. el nier. ne. eeeiired: te7 the levier ends. ei. atte. ie, n. tenerla nrQi/idedwih Zones ef. nexiire by te.. ne V ntelies. 6.8. in. iteeiciefianeee: the. nenes of the notches in the, difieren@ struts being in segarate nlaneS.-. e ennnerting erin provided. by saar/,e911 vvieles 6.9: le. lnelllted Within. the tube in, n

hereinafter. deeeribedi 'Erweiterte ineinmaintain ti-.iefwelee inenetenreler tio .A. Spring 1.2. has. ite lower. end eeeilreii. by anni.. welding er anilether desired. manner. te trnneveree rnenilten lef Its uriner. end envi-verts een lt iis/.nien bears against. the enges. ef tiene 6.9..- Geniaete 4.0. and. lil beine. siinnerten ne. nereter tere.. described by electrodes er lende 3.6. and 3.1., itiellews. that. it. 'erin 6.9 is weken., ber. it.. WillA eeeethe-Snnerieel element. 4.3 te-Separate @entente 4,@ and 1M'.5

The; ali-m the. tiro, struts. the zone. ei their 69 is supported` by. the leftv hand strut viewed. in Fiel llf by..- Springs 1.4 andV 1.5.- 'Spring 1,41- ie eennlen te the. lower- Siirfeee ei trenSi/.eree member; 'H ane.V has its. outer enel secured. toy a lereelset. 1.6. Willen is tiirn attached. te.. the. rear ei. the left han@ Strut Spring. 151e termen Wltn en. enening. tlirenen which. Spring 1,4 pensee 'Lhis- Spring. liet. its lower part. Seenred. t0 the, in.-

faee ef the lett hand. Stint-` Tne uriner end et enrinel5.. is. tenured te the eine. ieee. et traneverse. member; il adjacent the rear face of the etrirteS-Wnie .,iennder eensiderntien..

e. bracket. 1,-1 ie tenured. te the enter fate. ei. the night hand strut 65 as inFig, l1. Theupper arm of. ei: e. teneveree. serine strip. it.. The. inner ene of that. Str-.in isseenred tej transverse. ineinher il in e tiene. altere.. the piene Wiiien. tl-.ie inner ene. ei 1.4 it eeeiiree. te that. member. In eeinrnen Strin tit. Strip le passes threiien the enenina ermee. in thestriit eeieeent-tiie. linee. ei. the Inherited rieten Thus., traneveise. member il liee Siileetentielly in. the nlene ei tneee. netenes and heeeeenredteits. nerinherel. fete. the. Sniinee '1.4, wenn 18. Again the Securing. ef.. the. Parts is preferably-effected by. spot Welding.

When 'Shell er tesine 2.0. Siileieetei. te. the aetiener. lient it.. expander. Deete the inet. that the et nte e5 here alert eereirieient. 0i. ernennenwit ef ltreekets. le and 1.1 will be lnereaeed.- Tniewill here the. effeet. ef. inni/ine Snrine. Stripe 1.4 enllt outwardly therebyv rete-.tine treneyeree inernlier 1.1L. Tee-"initier beine. attentie@ te. the. Went. nrevidinetne ennnertine erin. 6.9. this will; be ret een retatien will. eener. in. e Clockwise iireetien. VTrierentre eentnete. 40. endet will. rernein engagement A. eenling et; the Stelt er ca g 2j!A vvfqill result in a: reverse action ofthe pa sy nel the rotation of arni 69v in a Counteryltor'zifzvtvise'diretion. es soon as'bar 1-3 engages elginent'tl'tniS will. ei: entree Serve. te eenreite cetaetsttfandtl. an@ enentlie. eireiiitwill, be 'iinsiersteetl freni. e. eeneielerntien 0f this street-,rire the height of transverse mernher 1J; be saidjto constitute the short arm of eierer ai; wnien. trie iene erin it virtually. ine fini le.; tn, et; the ennnertine erin 'er Webs. 69- ,.lie.. lewe. ende. ef. etnite e5.. being attatlietl t0 tite. ine etrine eri-et. et neinte nneenally spaced from the center,itfpiiowsthat their ilocatien.. relative t0 tneneint definenA er the. nene et iiinetnre et tneee. nienniing enel. the Snell er tebe- 2e.- will net be tire.-

Gentenuenttly iin-.deratiiiietnient the neeitien et annV 6.9, iS.

ie. breenet nes attached. te it the. enter end itlfollowsthatthedistanee between the4 outer ends Y ent; teftl're Strips. 64.' nach. ef. tliev stints -ell.n.neetl..v eeerdlnelr the temperature. Setting red e. nienner. einiiiar te tintnere et tl'ie.. earlier. neiireS..-.

In niet. 1.4. and. 1e e Strutture. nee. been. eltern Weigh generalita corifeenende t9'. that. nstregten nia. e. new this terni. ef; d...viee,tne Strut. le; eateries.. taneentieily entrees tire. eating et nein altere. its. V. rieten 8.0 eine. tenne esi er.. 8.1. einen. ite. endeeeenre 'f nreeinefefnefeee tiene 'it eeiireii t.

Qi. niet. it. a. peint below, in.. neen. in. 'inse nennen. te.. tine neri.. ei' ine. Strut. it. e. tering' t iinn'er enel. n. ereteber te'leeelne 8.2. Qenteete. tl'enld; te. are! prei/idee; the latterA beine, ennnertee: nennen electrode' f 'leest 81 ertensi'ng through tlileeap ef. the ii'ni..t. Tie eeeennlee. tliie een has. Within. the.. bedr ef. the devie n een.. iiiliien. may be. brideedtly. ef eleeebeetfsg- Bel@ this een 'lead' BBQinenntS. the tering. 4*

iinieli s iinnert tine. ennerieljeiernent tte be engaged..- by, bei: til nnsitnne eniit. tentent. A

Jaeketeaiiitliin. tnesleeve ite neetine eieinent entre ne e teilteand eleevle lill-, "One end. ef

tnie Geil. 1.5 nne te@ with lendf Bein. elenee ef been.. te. its. een' el ennes'ilte'idof the. een is. erinnerte... witn lead. 8.8 at'enirt inerenti. tneennwnieliis ienne# in the Seine- Wnen. eleetr'eties' er 'lende Si" and 8'9" netted. te e. Sentite ei eleetrieal.niserantits eentaete. 8.5. and.. te. are engagement, e'iiren't will aow through e011` gp. pgseqgntiy shil- 6r inne. 2.0. enel. tine. .enrreiindine ined-itin inline heated.- Under tlie. eirennietane 'the 'tube xviii; increase, in agrialiength, 5i amcV stift it nai/ine. their enter ende. enenedj 'eins't ninvernent'. with. retneet te. 'trie eliell. er 'tubeeine in e. in r .Similar te. that. eheivnin nieitielleiie. t, manuel, eeiuetnient et tne'reenense renee.. ef. the. ineenenie'in niet' te reterted to as heretofore described in,- the yearlier 'fi're Wlientn. .ernperetii e.. risente aiieintiihefre the teniente, eenarate, the new eizeurrent 'through coii Si):i is interrupte and inrthentenwp'ra/te rise is prevented. rihe In qinsqrrfiidillthe unit. niet e e material netin'e'liien ther'- rnal cvondtictlvlty. It may he -au'Mr 'ietalilocll''in innen in@ Sittin. nine nie enneirwiiheut being metal. The'tuh or shell bemgthe temperatureresignnsive element offthe thermostat as weil as the only heat-transfer link between the heating element alicic the siirrouhdi-ng medium, the colipling is such that the response is very rapideand the temperature diierentiaiwveiiy small. As4 is anparent, when the tube has cooled to'an adequate. extent, contacts 8,5 and 86. will: again engage. When' this oceurstthe heating.- element of the thermostat Wil-i again he. energized. as. afore described to. thus. provide controlled heating of the surrounding medium.

Finali-yreferring to Figs. 1.6, H and 18 there has been shown a formof: mfmntiilg.for thermostats of the typer herein embraced andwhich mounting wii-i'serve to admit of a ready` adLiustnient of: the` parts.l when is necessary. Also 1t vviii serve to groperlyvsupportthe nechaism Linder el-l'eireiirneteneeees. been strewn. in.' Fieeflft lfn'erbe "Q1 @mariene es. also erteilte tnreiien ployed and disposed adjacent a base 93 preferably formed with side anges 94. Straps S5 and 96 may extend outwardly from this base and be secured thereto by, for example, spot welding. The reduced end portion 22 of unit is disposed adjacent strap 95. To provide a clamping struc ture at this point bolts 5S may extend through this strap one to each. side ci bar 22. These bolts also extend through a bar Si which engages the rear face of constricted portion 22 and is in turn engaged by nuts 98. rIhus, it is obvious that the reduced end or" tube 2c may be iirmly supported and restrained from moving.

Adjacent the opposite end of base 93 a spring 99 may be furnished which bears against the rear of tube 20 and urges the same outwardly towards the inner face of strap 96. This part of the strap mounts a nut it through which a bolt or set screw lill extends. The latter also extends through an opening in the strap 95 so that it may bear against the outer face of tube 2Q. The leads 3G and 31 of the latter are connected to prongs |532 which extend through openings in base S3 and are supported by a mounting block I D3 of di-electric material.

As is apparent, with a unit supported in this manner its upper end is-as afore brought outrestrained from moving. Its lower end is capable of swinging movements. An operator desir-- ing to adjust the parts will simply rotate the screw Hi8 in clockwise or counterclochwise direction. According to the direction of such rotation the lower end of the unit as viewed in Fig. i6 will be forced towards base 93 or else urged in the direction of the inner face of the outer strap portion 96. Therefore, a manual adjustment of the parts will occur as heretofore described in connection with Figs. l to 5.

As will be understood, the teachings of the reversed structure shown in Fig. 10 could be incorporated in the several other forms, and excepting only that illustrated in Figs. 14 and l5. Also, while in many respects it is desired to completely enclose the several contacts and mounting operating structures thereof in a tube, the i latter might have openings or fail to provide an enclosure for these contacts and associated parts. Therefore, except where otherwise dened by the claims, the term ,shell is to be construed as a mounting member having a diierent coeiicient of expansion than that of the several arms, strips, etc. and regardless of whether an enclosure is provided or not.

Thus, among others, the several objects of the invention as specifically aforenoted are achieved,

Obviously numerous changes in construction and rearrangement of the parts might be resorted to without departing from the spirit of the invention as defined by the claims.

I claim:

l. A thermostat including in combination a shell formed of metal having a high co-eiicient of expansion, a strut element having one of .its ends fixed against movement with respect to said shell, a strip element also having one of its ends fixed against movement with respect to said shell at a point spaced from that at which said strut element is so fixed, at least one of said elements being formed or" metal having a low coeflicient or? expansion, a contact supported by said shell, a second contact movable with respect to said first named contact and cooperable therewith, an actuating arm for said movable contact carried by said strut element at a point intermediate the length of the latter and said 10 strut element being provided with a zone of ilexure at a point adjacent the point of mounting of said arm.

2. A thermostat including in combination a shell formed of metal having a high co-encient of expansion, a strut element having one of its ends xed against movement with respect to said shell, a strip element also having one of its ends fixed against movement with respect to said shell at a point spaced from that at which said strut element is so fixed, at least one o1 said elements being formed of metal having a low coefficient of expansion, a contact supported by said Shell, a second contact movable with respect to said rst named contact and cooperable therewith, an actuating arm for said movable contact carried by said strut element at a point intermediate the length of the latter and said strut being formed with -a notch and an opening adjacent the point of support of said arm to furnish a zone of flexion within said arm.

3. A thermostat including in combination a shell formed of material having a high coeincient of expansion, a pair of struts having their opposite ends connected to said shell, said struts having a low co-efcient of expansion, a Contact cariied by said casing, a cooperating contact movably supported adjacent said first named contact, a rockable actuating arm movable with respect to said latter contact for shifting the same, means defining a pivot for said arm and means connecting said struts to said pivot-denning means for rocking the latter and said arm.

4. A thermostat including in combination a shell formed of metal having a relatively high co-eiiicient of expansion, an assembly including at least one part having a relatively low coefficient of expansion, said assembly being connected to said shell to have portions moved with respect to said shell as the latter distende and shrinks in response to temperature changes, electrical leads extending into said shell, a pair of contacts connected one to each of said leads, a spring interposed in at least one of the connections between one contact and its lead, a further spring carried by one of the moveable portions of said assembly, said further spring having greater resistance to flexion than said interposed spring and said further spring acting against the interposed spring to effect relative movements of said contacts.

5. A thermostat including in combination a supporting member, a switch carried by said member, a strip attached to said member acljacent one of its ends, a second strip attached to said member at a point remote from said first named strip, said strips having a co-eiilcient of expansion different from that of said member, a coupling structure connected to the unattached ends of said strips to be rocked thereby as said latter ends move with respect to each other and said member in response to changes in temperature, movement-magnifying means connecting said coupling structure with said switch to operate the latter as said structure rocks, said cou.- pling structure being disposed adjacent that end of said supporting member to which said nrstnamed strip is attached and at least the latter end of said supporting member being iiexible whereby the adjacent strip, coupling structure and switchmperating means will be laterally denected for a distance substantially equal to the :amount of deflection of the end of said support- ,ing means with respect to its body.

16. A thermostat including Tin combination a Jsupporting member, a switch carried by said member, a .strip attached to Said member vad- Sjacent one of its ends, a second strip attached to said member at a point remote from said 'firstjnamed strip, said strips having a vco-.eiic'ient of expansion different 'from that of said member, a coupling Vstructure connected to Ithe unattached `ends of said lstrips to be .rocked thereby as .said llat'ter ends move with respect to each other and said member in response to changes vin temperature, movement-magnifying means connecting said Vcoupling structure with said 'switch to operate 'the latter as said structure rocks, said cou- .pling structure being disposed adjacent that .end of ,said supporting member to which said .irstnamed strip is attached, at least the latter end o said supporting member being iiexible whereby the adjacent strip, coupling .structure and switch-operating means will .be laterally deviiected for .a distance .substantially equal Lto the amount of .deflection of the end of said support- ;ng means with respect to its body and means bear'ing against said supporting member .and s'hiftable in a direction substantially perpendic- 'ular 'to its axis 'for causing such ilexing.

17,. A thermostat including 'in .combination a supporting member, 'a switch carried by said member, a strip attached to 'said `member vad- `jacent .one of its ends, a second strip attached "to said member at a point remote from said 'rst- :named strip, .said strips having a co-emcient oi expansion diiierent l'from that of said member, 'a coupling structure connected to the unattach'e'd ends 'of said strips to be rocked thereby as said vlatter ends lmove with respect to each other and said member in response to changes in temperature, movement-magnifying means connect- .ing said coupling structure with 'said switch 'to .operate 'the Vlatter Vas said structure rocks, said coupling structure being .disposed `adjacent that end of said supporting member to which said first-named strip is attached, at least the latter end of 'said supporting 'member being exibl'e whereby `the .adjacent strip, coupling 'structure and switch-operating means will be laterally dei'lected for a distance substantially equal vto the .amount of deiiection oi the end of said supporting member with respect 'to its body, mounting means for'the latter end of said supporting member and adapted to retain the latter 'substantially against movement and .means associated with .said 'mounting means and bearing against said supporting member at a point substantially remote :from its flexible end to move in a direction substantially perpendicular to the 'axis of said supporting member `for causing such flexing.

l 8. A thermostat includmg in combination a shell "formed of 'metalh'aving a relatively high co- `ejiicient of thermal expansion, at least a part of Llll .said lshell being formed of material susceptible to deformation, an assembly including at least one part 'having a relatively low co-ei'cient of expans'ion, said assembly being connected to -said shell adjacent said vdeformable part and at a point spaced therefrom Ato have portions moved along a predetermined path of travel at `a highly amplified rate with respect to said shell in proportion to and in :response to its longitudinal eX- pansion and Vcontraction resulting from temperature changes, .said portions being also disposed to lbe moved along the same path at a lesser ,arnplied rate with respect to the shell 'by reversible lateral Adeformation of said part of the shell.

9. A thermostat including in combination 'a .shell `"formed lof metal having 'a Y'ben'dable re- .'stric'ted end ,portion and i'formed 'of `a metal embracing `a relatively high 'co-efficient VAof thermal expansion, 'a rigid element held A-by the restricted 'end portion of Asaid shell 'and extending into the unrestricted 'portion of said shell, Van fas- 'sembly including at least Vone part with ya relatively low co-efcient 'of expansion, saidassembly `being eXibly attached to the inside "end Aof 'said rigid element land also to the inside 'of "the shell near its opposite end, a `contact 'supported 'by said shell, a second contact `movable with respect to said `first-'named contact and cooperable therewith, an actuating 'arm for said movable 'contact 'forming part of vsaid assembly, said 'assembly being constructed 'so that the longitudinal expansion and contraction Voi the vshell resulting from temperature changes cause `a substantia'lly lampliiied movement at Vthe end of `.the actuating arm, and .also constructed so that mechanical'bending ci the restricted end portion of 'said shell will 'cause a relatively less ampliiied movement at the end .ofthe actuating `armalong the same path.

l0. A thermostat including in combination 'an elongated member, 'a strut 'member -having both ends fixed against movement with respect "to said elongated member, one of said kmembers being made of a metal having a relatively high coeiiicient of thermal expansion, the other having a relatively low expansion co-eicient, a contact (supported 'in xed relation to said 'elongated member, a 'second contact Vmovable with respect to said rst-named contact and cooperable therewith, an actuating arm for 'said movable contact carried by said strut member at a point vintermediate the length of the latter and said strut element being provided with a zone of exure at a point adjacent the point of 'mounting of 'said arm.

l1. A thermostat including in combination a supporting member, a 'strip connected to 'said member adjacent one end of the same, a strut having one of its ends connected to 'said member at a point remote from `that at which said strip is connected thereto, a pair of contacts `supported by said member, an element having an outer end cooperative With one of 'said contacts to. cause the same to move relatively to the other, 4said strip and strut being vformed of a material having a different co-efcient of expansion than said member and a coupling structure connecting 'adjacent ends of said strip, 'strut and Ielement to Yeacli other whereby minute Vmovements of the adjacent strut and strip 4ends with respect to each rother will cause 'the coupling 'structure to vrock and the outer end of saidv element to move through a relatively large path and cooperate with said one contact.

12. A thermostat including in combination a Vsupporting member, a strip connected to Vsaid Vmember adjacent one end of the same, a `strut having one of its ends connected to said member 'at a 'point -remote from that at which said strip is connected thereto, a pair of contacts supported `by said member, an element having an outer end cooperative with one of said contacts to cause the same-to move relatively to the other, said strip and strut being formed of :a material having a difierent co-eiiicient of expansion than said member, a "coupling structure connecting 'adjacent ends of said strip, strut 'and elementtc each other 'Whereby minute movements ofthe adjacent strut and strip ends with respect to each other will cause the coupling structure to rock and the outer end of said element to move through a relatively large path and cooperate with said one contact, said coupling structure being disposed adjacent that end of the supporting member to which the strip is connected and such end of said member being formed of flexible material whereby it may be deected in a direction substantially perpendicular to the axis of said supporting member to laterally shift said strip, coupling structure and element with respect to the axis of the same.

13. A thermostat including in combination a supporting member, a Contact carried thereby, a spring also carried by said supporting member, a second contact cooperative with said nrst contact and mounted by said spring, an actuating assembly connected to Said supporting member and having a co-eiiicient of expansion dii-ferent than than of the latter, means forming a part of said assembly and supported for rocking movement as temperature variations cause expansion and contraction of the parts and a second spring more powerful than the inst-named spring, said second spring extending from said assembly to be swung thereby to act against the thrust exerted by said rst spring and to relative movements of said contacts.

14. A thermostat including in combination a side wall providing a supporting member, a strip having an end secured against movement with respect to said side wall, a strut having one also connected to said side wall at a point spaced from the point of connection oi' the strip therewith, said strip and strut being formed ci a material having a different co-efcient of expansion than the material coupling structure connected to the opposite ends of said strut and strip and supported for rocking movements in response to expansion and retraction of the parts, a switch-operating element connected to said wall and extending therefrom and means projecting from said structure to be swung' thereby into engagement with said operating element to cause a functioning of a switch connected therewith.

15. A thermostat including in combination an elongated member, a switch carried by said meinber, a strut element having one of its ends xed against movement with respect to said elongated member, a strip element attached to said elongated member at a point remote from that at which said strut element is so iixed, said strut element having a co-eiiicient of expansion diierent from that of said elongated member, a 1flexible connection between an end of strut element and one end of said strip element, an actuating arm carried by said strut element at a point intermediate the length of the latter for operating end of said supporting member, a

if said switch in response to changes in temperature, said strut element being provided with a zone of iiexure at a point adjacent the point of mounting of said arm, and said elongated member being iiexible at a point adjacent to the point of attachment oi said strip element, whereby that end of said strip element which is nexibly connected to said strut element can be moved in a direction substantially perpendicular to the axis of said elongated member, thereby changing the temperature at which said arm will Operate said switch.

16. A thermostat including in combination a supporting member, a switch carried by said member, a strip attached to said member adjacent one of its ends, a second strip attached to said member at a peint remote from said nist-named strip, said strips having a cc-enicient of expansion dir"- ferent from that of said member, a coupling structure connected to the unattached ends of said strips to be rocked thereby said latter ends move with respect to each other and said inember in response to changes in temperature, movement-magnifying means connecting said coupling structure with said switch to operate the latter as said structure rocks, said coupling structure being disposed adjacent that end of said supporting member to which said first-named strip is attached, at least the latter end of said supporting member being flexible whereby the adjacent strip, coupling structure and switch-operating means will be laterally deflected for a distance substantially equal to the amount of deflection of the end of said supporting means with respect to its body, clamping means for the latter end of said supporting member, and means associated with said clamping means and bearing against said supporting member at a point substantially remote from its flexible end to cause flexing of this end in a. direction substantially perpendicular to the axis of said supporting member.

WXLLIAM C BROEKHUYSEN.

References Cited in the nie of this patent UNITED STATES PATENTS Number Name Date 1,378,730 Shoenberg May 17, 1921 1,827,102 Penn ct. 13, 1931 1,933,083 .Ackerman Oct. 31, 1933 1,942,002 Romanelli Jan. 2, 1934 1,976,954 Mantz Oct. 16, 1934 1,992,755 Petersen Feb. 26, 1935 2,24%,915 Marvin June 10,1941 2,402,2fi0 Crise June 18, 1946 2,441,725 Smith May 18, 1948 2,516,502 Altman et al July 25, 1950 

